1. Technical Field
The present disclosure relates to an articulating surgical apparatus. More particularly, the present disclosure relates to an articulating surgical apparatus including a locking device configured to lock the surgical apparatus in a non-articulated configuration.
2. Description of Related Art
Surgical instruments that are configured to articulate or bend are well known in the medical arts. Surgical instruments of this nature are utilized in many surgical procedures. For example, laparoscopic, endoscopic, or other minimally invasive surgical procedures are just a few of the many surgical procedures where articulating surgical instruments may find use. When utilized in such procedures, the surgical instruments may include a housing, a handle assembly, an articulating shaft, a device for articulating the shaft, and an end effector including a pair of jaw members.
As can be appreciated, the relatively small operable working space that is created within a cavity of a patient during a surgical procedure often makes it difficult for the surgeon to position the jaw members adjacent or close to target tissue. The articulating shaft allows a surgeon to position the jaw members adjacent target tissue.
Various articulating devices or mechanisms may be utilized to articulate the shaft. For example, some surgical instruments utilize one or more articulating cables or tendons that couple to one or more articulation links on the shaft. Typically, the cables or tendons provide a mechanical interface from the one or more articulation links to an actuation device, e.g., rotatable dials, disposed on the housing and/or handle assembly of the surgical instrument such that actuation of the actuation device moves or articulates the shaft about the articulation links. In particular, the cables or tendons are “pulled” or otherwise manipulated via one or more mechanisms in the handle assembly or the housing to articulate the shaft about the articulating links.
Under certain surgical scenarios, it may prove advantageous to maintain the shaft in a relatively fixed or stationary position, such as, for example, when positioning tissue between the jaw members or when the shaft is inserted through a trocar or cannula. Locking the cables or tendons so that the shaft is prevented from articulating typically requires eliminating, what is commonly referred to in the art as, cable or tendon “stretch” from the cables or tendons. Cable or tendon “stretch” is the ability of the cable or tendon to stretch under a predetermined load. To remove this cable or tendon stretch, the cables or tendons are typically highly loaded in tension. Removing this cable or tendon stretch limits and/or eliminates “post lock” articulation. However, due to the length of the surgical instrument and, thus, the corresponding length of the cables or tendons between the articulating links and the actuation device and/or locking device, a fairly large “spring rate” exists with a corresponding “stiffness” penalty being observed. That is, overtime, subjecting the cables or tendons to high load tension reduces the stiffness of the cables or tendons and, thus, the overall stiffness of the shaft. As can be appreciated, reducing the “stiffness” of the shaft may result in the shaft not functioning in a manner as intended.